Locomotive boiler superheater



Jan' 9 1940' L. B. JONES TAL LOCOMOTIVE BOILER SUPERHEATER Filed Aug.l2, 1938 5 Sheets-Sheet l @6i 1l la? I? zii *1N f1 "6 27 4 :EQgl i W 55wfg? 92 i u L. ma 1. A

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Lln db'. 01u25 Q MZ] j? By, -Razlvhyimzmfg ATTORNEYS.

Jan- 91940- L. B. JoNEs ET AL LOKCOMOTIVE BOILER' SUPERHEATER Filed Aug.12, 1938 's sheets-sheet 2 1,3 .l INVENToRs.- Llayd Janes c By t/iii;735i/nia,

ATTORNEYS.

Jan. 9, 1940. L. B. JONES e: AL 2,186,904

r LOCQMOTIVE BOILER SUPERHEATER Filed Aug. l2, 1938 3 ShetS-Sheet 3 W ITNESSES INVENTORS.'

Patented Jan. 9, 1940 PATENT orner LO-CO-MTIVE BOILER SUPERHEATER.

Lloyd B. Jones, Altoona, and Ralph T.4 Strattan,

Philadelphia, Pa., assignors 'to The 'Pennsylvania Railroad Company,Philadelphia, Pa., a

corporation of Pennsylvania Application August 12, 1938, Serial No.224,495

7 Claims. (C1. 122-462) This invention relates to steam boilersuperheaters, and especially to superhea-ters compris- ;r ing loop tubeswhich extend from ,a smoke box or lend ,chamber of a boiler into boilerlues or re tubes that open into the chamber. `Such superheaters are muchAused with steam locomotive boilers of horizontal fire tube type, andthe invention is explained hereinafter with particular reference to thiseld of use. The -invention aims at improving the arrangement andconstruction of suchsuperheaters, at securing high 'superheat, a-tminimizing the pressure drop of steam in the superheater., and atfacilitating inspection, repair, and replacements of superi heatertubes. IOther featuresand advantages of the invention will appear fromthe following devsubheader being broken away.

Fig.V II is a front view of a locomotive boiler equipped withsuc-h Aasuperheater, the boiler shell being in section, with portions brokenaway,

and lvarious parts .of the superheater being in section, broken away,and removed.

Fig. III isa fragmentary front view similar to Fig. II, but with theforward header and subheaders of the superheater removed.

"Fig,v IV shows a vertical section through a portion of one of the mainsuperheater headers,

taken as indicated by the line and arrows IV-IV in Fig. I.

, Fig. V shows a vertical mid-section through one of the 4mainsuperheater headers, taken as indicated by the line and arrows V-V inFig. III.

Fig. VI shows two of the subheaders of the ysuperheaterin horizontalsection, taken as indicated .by the line and arrows VI-VI in Fig. I,

portions of the .superheater tubes connected to these subheaders beingalso shown.

Fig. VII is a partial View of the mainsteam delivery header and of thesubheaders of the superheater from in front, looking rearward andupward, as indicated by the line and arrows VII-VII in Fis. I, most ofthe main steam supply header being omitted to avoid confusion.

, In Figs. I, II, and III of the drawings, Illv is the yfront tube sheetor nue sheet of a locomotive boiler of 'fire-tube type; Il vis the mainboiler shell; I2 isa forward extension of the main boiler shell,

' enclosing the front end chamber or smoke boxI i3; i4 .are the firetubes extending :through the water spaceof the boiler, and openingthrough the iiue sheet il) into the smoke box i3; .and l5 are the largefire tubes or flues, that accom' modate the steam tubes I6 of thesuperheater, which are shownas single ,Ueloops As shown in Fig. II, .theiiues i5 are arranged in vertical rows, and so likewise arethe'loop-tubes it, of which there'are two in each iue. 'The superheateris shown as .comprising transverse main steam supply and deliveryheaders 23 and 2l adjacent one another in the top of the smoke box, withsets `of steamsupp-lyfand delivery sub'- headers 22 andv 2 3 extendingdownward from them in iront of the flue sheet it. As .shown in Fig. I,the upper ends oi the subheaders 22 and` 23 voverlap in front of thecorresponding main headers 28 and 2i which these .subheaders mainlyunderlie, and are attached to .them from' in front, preferably on aslope as hereinafter described.

'As -best shown in Figs. IV, the main steam attached `to the frontuesheet lil and connected to the 2boiler dry-pipe 2t by bolts 2i, moet ofwhich take through said-flange. However, as shown in Figs. III, IV, andV, a portion of the flange 25 is merged with the rear wall of the header20, and the nuts 28 for the bolts 2i in this portion are accommodated'intubular barrels 29 forming part of the 'header casting, and opening fromthe front o-f the-header back to its rear end around the bolts, so thatthe nuts 28 may be applied and removed with a socket wrench introducedthrough these barrels. Asshown'in Figs. III-V, the main supplyheader 2ttapers to either side from the inlet opening 2d. Along its lower frontedge, this header 2li has a series of openings -and seats for thesubheaders 22, rconsisting of short necks 3U Vwi-th flanges or ears 3lat their ends for the attachment of the subheaders 22, by means offastenings'such as bolts 32 taking through the fla-nges'or ears 3l andthrough similar flanges or ears 33 on the upper neck portions 34 of saidsublieaders 22. As most clearly shown in Fig. I, these openings andseats lie slope v rearward and downward toward the nue sheet l0, so thatthey are presented obliquely forward and downward away from the lfluesheet.

The main transverse steam delivery header 2l is mounted in the 'top ofthe smoke box i3 in front of (and somewhat above) the steam supplyheader 20, substantially over the steam supply subheaders 22, and hasoutlet openings and seats for ythe attachment of the subheaders 23,consisting of downward extending necks 35 with flanges or ears 36(similar to the flanges 3| of the necks 30) for the attachment of thesubheaders 23, by means of fastenings such as bolts 31 taking throughthe anges or ears 36 and through similar anges or ears 38 on the upperneck portions 39 of the subheaders 23. As in the case of the supplyheader 2U, the openings and seats of the delivery header 2| lie on asloperearward and downward toward the flue sheet I0, and are thuspresented obliquely forward and downward, away from said flue sheet. Asshown in Figs. I and II, the main steam delivery header 2| is located ata substantial interval in front of the main steam supply header 20, soas to minimize direct radiation of heat from the one header to theother, but is attached to the header 28 (and supported therefrom) bybolts 46 taking through bracket lugs 4 4| on the two headers. The endsof both main headers 20 and 2i are also provided with supporting bracketfeet 42 resting on and bolted to brackets 43, which are riveted to theinterior of the smoke box shell l2.

As shown in Figs. I, II, and III, the subheaders 22, 23 of both setsabut and are attached to the corresponding main headers 26, 2| atdifferent levels, preferably on a slope (as of about 45 degree) and in acommon plane.

As shown in Figs. I, II, and VI, the subheaders 22 and 23 are spacedfrom one another by a substantial interval, to minimize direct radiationbetween them, but are attached to one another and kept in properrelative positions by bolted connections between bracket lugs 44, 44 ontheir adjacent sides. While the necks 30 and 35 of correspondingsubheaders 22, 23 of the two sets are directly aligned one in front ofanother as shown in Fig. II, the lower portions of such correspondingsubheaders are oppositely offset, out of line with one another, so thatthe ends of each loop tube I6 may extend and be connected directly intothe rear sides'of these subheaders, as shown in Fig. VI.

Preferably, the loop tubes |6 are simply elongated U-tubes in which thesteam makes a single pass rearward from the subheader 22 and forwardagain into the subheader 23, each pair of subheaders 22, 23 serving onevertical row of the tubes. In effect, each such pair of headers 22, 23with their interconnecting tubes I6 constitute an independentsuperheater unit, traversed by the steam in parallel withthe other suchunits, and removable or insertible in place by itself, as explainedhereinafter.

Important features of the construction shown are the location of bothmain headers 20, 2| at the top of the smoke box, and the detachabilityof the subheaders 22, 23 there; for in prac-tice the smoke box containssome parts which it would be undesirable to remove to obtain access tojoints and securing devices in the lower portion of the smoke box, aswould be necessary if one.

of the main headers were located there. Furthermore, it is much easierfor a workman to work upward or overhead on securing devices for thesubheaders than to work downward on them. Important also is the lateraloffset of the lower portions of corresponding subheaders 22, 23, topermit direct connection of the tubes |6 of each vertical row directlyto their lrear sides, while their upper portions or necks 34, 39 arealined,

so that access may be had between the front necks 39 to the fastenings32 associated with the rear necks 34, etc.

Another important feature is the attachment of the subheaders 22, 23 tothe main headers 20, 2| at different levels, and preferably on a slope.If the heads of the fastening bolts 32 for the rear headers 22 were atsubstantially the same level as those for the bolts 31, it would beimpossible to work on them with a wrench between the header necks 34, 39and behind the bolts 31; and even with these nuts at different levels,it would be very dicult to work on them between the header necks if theaxes of the bolts were vertical. With the arrangement shown, however, asocket wrench can be introduced (on a slope upward and rearward) betweenthe front headers 23, and can be applied and operated on the nuts of thebolts 32 for the rear headers, since the nuts for any of the bolts 32,31 are exposed and visible between the headers 22, 23 at either side ofthe plane of the bolts. The sloping attachment of the subheaders 22, 23to the main headers 20, 2| also makes it very easy to withdraw forwardany superheater unit (composed vof a vertical row of tubes I6 and theheaders 22, 23 to which they are connected), by a simple forwardmovement, without disturbing any other subheaders.

Having thus described our invention, we claim:

1. In a superheater for a horizontal ue boiler, comprising loop tubesextending from a smoke box or end chamber, into which the boiler luesopen, back into said lues, the combination of a main transverse steamsupply header in the top of the smoke box secured to the end of theboiler above said iiues, with a set of detachable downward extendingsteam supply subheaders for serving said loop tubes overlapping andattached to said main steam supply header in front thereof; a maintransverse steam delivery header in the top of the smoke box, detachablymounted on said main steam supply header; and a separate set ofdetachable steam delivery subheaders, for

serving said loop tubes, overlapping and attached to said main steamdelivery header in front thereof, and extending downward in front ofsaid steam supply subheaders, and detachably secured to the latter, saidloop tubes interconnecting corresponding subheaders of the two sets;whereby, on detaching said main steam delivery header and said steamsupply subheaders from said main steam supply header, the entiresuperheater, excepting said main steam supply header, can be withdrawnforward from the smoke box as a unit, while on detaching correspondingsubheaders of the two sets from both the main headers, said detachedsubheaders and the loop tubes interconnecting them can be withdrawnforward from the smoke box without disturbing other parts.

2. In a superheater for a horizontal flue boiler, comprising loop tubesextending rearward from a smoke box or end chamber, into which theboiler fiues open through a flue sheet of the boiler, back into saidflues, the combination of separate adjacent transverse main steam supplyand delivery headers in the top of the smoke box in front of said fluesheet, said main headers having subheader openings lying on a slopedownward and rearward toward said flue sheet and thus presented downwardand forward in the smoke box, away from the ilue sheet; separate sets ofsteam supply and delivery subheaders for said loop tubes arranged infront of and underlying the corresponding main headers, with intervalsbetween their upper portions, and having openings in their said upperportions presented rearward and upward to the said main header openings; and fastenings accessible from below and in front o-f saidsubheaders through said intervals between their said upper portions anddetachably securing the subheaders to the corresponding main headers incommunication with them through the aforesaid main header and subheaderopenings; the subheaders of said sets being separable from the mainheaders, when detached, by mere forward displacement, by virtue of theirrelations to the main headers as hereinbefore set forth.

3. In a superheater for a horizontal iiue boiler, comprising loop tubesextending rearward from a smoke box or end chamber, into which theboiler ilues open through a flue sheet of the boiler, back into saidlues, the combination of separate adjacent transverse main steam supplyand delivery headers arranged in the top of the smoke box in front ofsaid iiue `sheet and one in front of the other, and having subheaderseats lying on a slope downward and rearward toward said flue sheet, andthus presented downward and forward in the smoke box, away from saidflue sheet, thesubheader seats of the forward main header lying in frontof and above those of the other main header; and separate sets of steamsupply and delivery subheaders for said loop tubes arranged infrontofand underlying the corresponding main headers, with'intervals betweentheir upper portions, and having their said upper portions detachablysecured` against corresponding main header seats, so that the jointsbetween said subheaders and the main headers are accessible from belowand in front through said intervals between the said upper portions ofthe subheaders. l

4. In a superheater for a horizontal flue boiler,

comprising loop tubes extending from a smoke versely of the smoke box,out of fore and aft align-l ment, so that the loop tubes in the boilerues may extend forward to the rear sides of these lower portions of thesubheaders of said sets and be connected into them; and means fordetachably connecting said sets of subheaders to the corresponding mainheaders, the connecting means for the subheaders of at least one of saidsets comprising fastenings exposed forward in said intervals, and thusaccessible from in front between said upper portions of the subheaders.

5. In a superheater for a vhorizontal ue boiler, comprising loop tubesextending from a smoke box or end chamber, into which the boiler iiuesopen through. a iiue sheet of the boiler, back into said iiues, thecombination of separate adjacent transverse main steam supply anddelivery headers in the top rof the smoke box in front of ksaid fluesheet; and separate sets of steam supply and delivery subheaders, oneset in front of the other, underlying and detachably attached to thecorresponding main headers on a slope downward and rearward toward saidnue sheet; the upper portions of corresponding subheaders of said setsbeing substantially aligned, fore and aft of the smoke box, withintervals between those of each set through which the joints betweensaid subheaders and the main headers may be reached from below and infront, while the lower portions of said corresponding subheaders areoffset relative toA said upper portions, transversely of the smoke box,out of fore and aft alignment, so

adjacent transverse main steam supply and dei livery headers in the topof the smokel box, inA

front of said flue sheet, said main headers having externally iiangedsubheader necks, with intervals between them, presenting their openingsor.

mouths downward and forward in the smoke-box, away from said iiue sheetbut on a slope .downe ward and rearward toward it, the mouths yof thenecks of one main header lying in front of and abovel those of the othermain header, substan-` tially in fore and aft alignment with them;separate sets of steam supply and delivery subheaders having externallyiianged upper portions, with lateral intervals between them, arranged infront of and underlying the corresponding main header said upperportions, transversely of the smoke box,

out of fore and aft alignment, so'that the loop tubes in the boilerflues may extend `forward to the rear sides of these lower portions of'said subheaders and be connected into them; and bolts taking through theiianges of corresponding main header necks and subheaders anddeta'chably securing the subheaders to the main headers; said boltsbeing thus accessible from below and in front of said subheaders throughsaid intervals between the subheader necks, and the subheaders of bothsets being separable from the main headers, when detached, by mereforward displacev ment, by virtue of their relations to the main headersas hereinbefore set forth. x 7. In -a superheater for a horizontal flueboiler,

rcomprising loop tubes extending rearward from,

a smoke box or end chamber, into which the boiler flues open through aue sheet of the a slope downward and rearward toward it, thev necks ofone main header lying in front ofand Iabove those of the other mainheader, substantially in fore and aft alignment with them.

LLOYD B. JONES. v

RALPH T. STRA'I'IAN.

